|Shields jr, Fletcher|
Submitted to: Journal of Environmental Management
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/27/2002
Publication Date: 5/13/2003
Citation: Schaff, S.D., Pezeshki, S.R., Shields Jr, F.D. 2003. The effects of soil conditions on survival and growth of black willow cuttings. Environmental Management. 31(6):748-763. Interpretive Summary: Native woody vegetation is an attractive alternative for streambank erosion control because of economic and environmental factors. Willow species are especially useful because they may be propagated by planting large cuttings (posts) that stabilize steep, eroding banks during the critical period of plant establishment. However, survival rates for many willow post projects have been disappointing. We studied willow posts planted along Twentymile Creek in Lee County, Mississippi in 1998 for two years. Study plots were selected to represent a range of bank slopes, soil types, and elevations. Willow posts planted in moist, sandy soils grew 10 to 15 times as much as those planted in silt-clay soils on similar slopes. These results suggest factors that should be included in a simple site evaluation procedure that could be used to decide where willow post planting will be effective.
Technical Abstract: Current streambank restoration efforts often incorporate native vegetation. However, in many cases harsh site conditions limit success. A two-year field study was conducted at Twentymile Creek, in northern Mississippi, investigating edaphic factors governing the survival of black willow (Salix nigra) cuttings used for streambank restoration. Low height growth, above-ground biomass production, and average leaf area were observed in willow cuttings grown in plots subjected to moisture deficits. However, sediment texture emerged as the dominant factor determining willow post growth, health, and survival. Shoot biomass, leaf biomass, and total above ground biomass were 15-, 10-, and 14-fold greater for posts grown in plots with sandy sediments relative to those grown in plots with similar moisture and soil redox potential but finer sediments. Average leaf size, average leaf mass and specific leaf area were all significantly lower in the fine textured plots (P=0.0001, P=0.0001, and P=0.0417, respectively). Our results strongly suggest that soil texture and moisture conditions can determine restoration success. Therefore, it is critical that site conditions are factored into the selection of project locations prior to the initiation of willow planting restoration projects.